What is the headwind component for a Rwy 13 takeoff if the surface wind is 190° at 15 knots?

To determine the headwind component when taking off from Runway 13 with a surface wind of 190° at 15 knots, we need to understand the relationship between wind direction and runway orientation.

Runway 13 is aligned at a heading of 130° (runway headings are based on magnetic north, rounded to the nearest ten degrees). The wind is coming from 190°, meaning it is a tailwind for Runway 13 since the wind direction is essentially coming from behind the aircraft as it faces the direction of takeoff.

To calculate the headwind component, we're interested in how much of the wind's velocity acts against the aircraft's forward motion. The headwind component is found by calculating the difference between the wind direction and the runway heading:

1. Calculate the wind coming from 190° subtracting the runway heading of 130°:

• 190° - 130° = 60°.

2. The tailwind component can thus be thought of as the wind blowing at 15 knots at an angle of 60° to the direction of takeoff.

3. To find the headwind component, you can use the equation for the wind component:

• Headwind Component = Wind Speed * cosine